Adma and Ackr3a regulate cardiac lymphatic vessel formation and function during heart development and regeneration.

Adma and Ackr3a regulate cardiac lymphatic vessel formation and function in zebrafish hearts, with adma mutants showing edema and dilated outflow tracts plus mis-patterned, reduced lymphatics.

• Why it matters: Cardiac lymphatics control fluid homeostasis and immune cell clearance, but how cardiac lymphatic vessels form during development and regeneration is unclear.
• What they did: Using spatial transcriptomics at single-cell resolution in zebrafish hearts, the study maps gene expression in cardiac lymphatic endothelial cells and tests adma and ackr3a mutant phenotypes.
• The result: Loss of ackr3a increases lymphatic sprouts, and during regeneration adma and ackr3a are expressed in epicardium-derived wound cells; neutrophil clearance is reduced in adma mutants but increased in ackr3a mutants.